Total Time Spent: ~21.5h

May 22nd

Start!

Got approval from alex yesterday and wrote down the BOM inso a csv today, also set up my repository with the journal and Readme and stuff, made a rough sketch for the first part(s) in class today :3 Design will definetly vary though, e.g ill add 6 screws and not 4 most likely

Sketch:

Session Time Spent: ~1h30mins

Basic structure design

Spent a bunch of time in fusion trying to figure out little details but ended up with a design for the component enclosure that im pretty happy with, attached below, making the screw holes next to the block (supposed to be the PSU) align with the edge of the psu so i can actually take it out was pretty painful, gonna have a hole there and thinking about maybe? adding rails to be able to kinda slide everything out for maintenance.

Also got info on what fuse i need for the psu iec socket (confusing but shoutout @Volkov08 for helping)

Session Time Spent: 2h

May 23rd

Getting first Electronics stuff down

So, today I wanted to review my stuff with steppers and so on and realized i might not have enough GPIO pins for all 6 stepper drivers + fan, lights,microphone, speaker, etc., after going on a journey looking up all the stuff i could do i decided to go for a PCF8575 i2c expansion module to control the steppers, turns out i2c is really cool for this. Found it and some basic components ill be needing on aliexpress, and pained myself with installing fritzing thrice with a bunch of problems for about an hour, got a pretty decent schematic down (not without going though a questionable amount of datasheets and manuals) though, attached below:

Session Time Spent: 3.5h

Trying Kicad!

Decided to try and set up kicad to make a custom PCB for the project, fiddled around with it for a while, but i think it might be overkill for now so ill stick with the fritzing schematic, made more progress on the CAD design of the base (added the thrust bearing slot (kinda??) and made a slot for removing/inserting the PSU)

Session Time Spent: 2h

May 24th

Continuing CAD Design

I might be rushing the electronics a bit without knowing how much space exactly id have to work with, so i think this should be the approximate design of the base for now, pic 1 is fully assembled with the PSU and the pi (no idea what height so i guesstimated ~1.9cm) in silver and green and the thrust bearing in silver, second pic is the thing on which the bearing will be resting. Decided to make it seperate to the base to minimize supports and quick changes to the design if needed. Also make a holder for the Axis 1 stepper which will need some M3 screws and Bolts, gonna add them to my cart today

Note: gonna update the BOM soon enough

Session Time Spent: 2.5h

PCB!

Now that i had the rough amount of space down, i decided to make a pcb so that all the drivers and such arent just loose over the place. This was my first pcb design ever btw so pls dont judge the schematic quality T.T, for some reason i decided to make it in fusion and not in fritzing or kicad (no idea why, maybe bc i wanted the 3d model, i think kicad has that too tho), but i think it turned out decently, i did have a bunch of trouble with finding the sizings of the drivers and the i2c module as i was getting the tmc chip and not the whole module. After literal hours of research i turned to frizing (only place that had the footprint of the tmc2209 and i2c module) and found out theres a ruler function with which i got the thing in about 10mins😭, attached pics below of the pcb, shcematic and pcb inside the base

Also, this might get pretty warm so im thinking of adding a fan for cooling all that somewhere (sides/(front/back) of the psu?)

Session Time Spent: 4h

May 25th

Joints 1 & 2!

Made a bunch of cad progress today! First, I made a round shape thing for the 1st joint that would also hold the second joint in the middle:

This turned out to be really impractical though because id need to magically insert a rod through the 2nd joint's arm part and then somehow also fit the servo next to it, so i decided to scrap that design and make a flat spinning base with a couple holders for the 2nd joint:

for this ill need some gears, a rod and bearings (i already have the bearings at home), which added up to ~10-15$. I think its worth it tho since its 5 pcs of each so ill be able to reuse that for future joints. I also added some heat inserts for attaching the servos and future stuff with screws instead of glue, and some cable sleeving for the cables. I should really update my BOM soon

Speaking of cables, my next step might be making holes for the cables to pass through, i think itll be quite a challenge tho since i cant really fit a slip ring into the first joint, so ill have to account for spinning for the first 2 servos, I think ill try to add a slip ring at the next joint though.

Also, thinking about joint 3, I might remodel joint 2 to just use 2 bearings without a rod for that so i can fit a stepper directly in the center of it without the rod interfering (totally not copied from a guy i found online :3)

Design today:

Session Time Spent: ~6h